When Herschel Walker contended last April that he could still play in the NFL at age 52, we pointed out that the former USFL and Dallas Cowboys star was best remembered by fans as the losing end of football's most lopsided blockbuster trade.

With a combined 18 players and draft selections involved, the Cowboys-Vikings trade remains the most iconic, franchise-shifting swap in NFL history.

NFL Media has produced a fascinating collaborative dissection of the background and aftermath of a trade that former Cowboys coach Jimmy Johnson refers to as "The Great Train Robbery."

Below are six of our favorite highlights from the long-form piece:

1. When Johnson was weighing the few assets on his roster, per NFL Media's Judy Battista, he briefly considered trading second-year wide receiver Michael Irvin, his former Miami Hurricanes star. Johnson opted against that option, on the advice of Oakland Raiders legend Al Davis.

2. Once Walker caught wind of the trade talk, according to Johnson, he threatened to retire and join the police department rather than leave Dallas. Owner Jerry Jones credits Walker with ultimately facilitating a trade that was viewed by both franchises as the pertinent move at the time.

3. Vikings general manager Mike Lynn was forced to pay through the nose for Walker because then-Browns general manager Ernie Accorsi joined the bidding out of spite. Lynn had tried to interfere with Cleveland's pursuit of a quarterback in the past, so Accorsi dialed up Johnson and drove up the price tag on Lynn.

"I was never serious," Accorsi told NFL Media, explaining that he already had Earnest Byner, Kevin Mack and Eric Metcalf at running back. "I was never going to make a trade for him."

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4. The Walker trade popularized the trade value chartdevised by then-Cowboys vice president Mike McCoy that went on to become the go-to tool for measuring trade value in drafts over the next two decades. According to Jones, the average NFL team enters the draft with 1,500 trade-value points in a given year. In the three years after the Walker trade, the Cowboys gained almost 8,000 points.

5. Without the Walker trade, Jones acknowledges, the $1.2 billion AT&T Stadium wouldn't exist in its present form. Without the Walker trade, there is no Emmitt Smith, Darren Woodson, Russell Maryland or Charles Haley in Dallas. Without the Walker trade, there is no Cowboys dynasty in the early 1990s.